We report herein the development of a stereodivergent route towards polyhydroxylated bicyclic azetidine scaffolds, namely 6-azabicyclo[3.2.0]heptane derivatives. The strategy hinges on a common bicyclic β-lactam precursor, which is forged by way of a rare example of a cationic Dieckmann-type reaction, followed by IBX-mediated desaturation. Substrate-controlled diastereoselective oxidations then allow the divergent preparation of novel iminosugar mimics.
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http://dx.doi.org/10.1039/c8ob01065j | DOI Listing |
Carbohydr Res
November 2024
Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, 695019, Kerala, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India. Electronic address:
Phytochemistry
February 2022
Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China.
Eight undescribed polyhydroxylated bergamotane-type sesquiterpenoids with bicyclic, tricyclic and tetracyclic systems, namely sporulamides A-D, sporulosoic acids A-B and sporuloketals A-B, along with three known analogs were isolated from cultures of the marine mud-associated fungus Paraconiothyrium sporulosum YK-03. The chemical structures of these sesquiterpenoids were elucidated by the extensive spectroscopic techniques of NMR and HR-ESI-MS. Assisted by the X-ray crystallography analysis and electronic circular dichroism (ECD) spectroscopic calculation and comparison, their absolute configurations were established.
View Article and Find Full Text PDFOrg Biomol Chem
August 2021
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
An efficient method for the synthesis of bicyclic iminosugars has been developed. The strategy is based on the partial reduction of sugar-derived lactams by Schwartz's reagent and tandem stereoselective nucleophile addition dictated by Woerpel's model which affords polyhydroxylated cyclic amines as key intermediates. Introduction of a vinyl or allyl group to the iminosugar produces diene derivatives that can be subjected to the ring-closing metathesis reaction (RCM) to furnish polyhydroxylated pyrrolizidine, indolizidine and quinozilidine derivatives in good to excellent yields.
View Article and Find Full Text PDFMolecules
July 2020
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
2,3,4-Tri--benzyl-D-xylopyranose was used as a starting material in the preparation of the corresponding triene, which underwent smooth cyclization to a polyhydroxylated hydrindane, as a single diastereoisomer. The analogous triene prepared from D-glucose did not undergo any cyclization even under high pressure.
View Article and Find Full Text PDFACS Omega
November 2018
Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Faculté des Sciences Fondamentales et Biomédicales, UMR 8601, CNRS-Paris Descartes University, 45 rue des Saints Pères, Paris 75006, France.
A sequence of oxidative cleavage/double nitroaldol condensation followed by a few simple synthetic transformations can lead to polyhydroxylated di- and triaminocyclohexanes from a readily available bicyclic hydrazine. This new synthetic route provides a simple and general access to densely substituted privileged scaffolds or fragments with a perfect control of their relative configuration.
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